For many applications it can be desirable to use moisture-curing compositions as adhesives, sealants or coatings having high initial strength. For example, adhesives with a low initial strength can have the disadvantage that the parts joined by an adhesive are to be kept in a fixed position up to the point that a certain strength has built so that they remain in the desired position.
There are different approaches for providing moisture-curing compositions with high initial strengths. Two-component or reactive warm- or hot-melt compositions, for example, warm- or hot-melt adhesives, so-called warm or hot melts, can be used. A combination of both approaches can also be used.
In this case, warm- or hot-melt adhesives can have the disadvantage that their viscosity increases dramatically immediately after application. Because of this, for example, corrections in the alignment of two substrates to be bonded after joining are complicated. Furthermore, for many applications these adhesives are generally not flexible enough to compensate for thermal expansion.
In addition to pure warm- or hot-melt adhesives, in which the moisture-reactive components are completely, or at least largely, present as components that are solid at room temperature, warm- or hot-melt adhesives can be used in which only a portion of the moisture-reactive components is solid at room temperature. Generally, they contain a reactive or nonreactive melt component in addition to a liquid, reactive component. In order to obtain compositions that have the best possible mechanical properties, reactive melt components can be used, wherein the spectrum of the same is rather broad. For moisture-curing compositions based on silane-functional polymers, reaction products of any polyol with polyisocyanates can be used, which are then reacted with amino- or mercaptosilanes. For example, such a composition is described in WO 2004/005420 A1.